Synthesis method of 3, 4, 5-trifluorophenol

A technology of trifluorophenol and synthesis method, which is applied in the preparation of liquid crystal material intermediates, pesticides, and pharmaceutical fields. It can solve the problems of ammoniation and hydrolysis catalysts, high safety risks, and environmental problems, and reduce by-products and tar. The effect of avoiding the generation of high-salt wastewater and reducing the risk of reaction

Inactive Publication Date: 2019-03-12
ZHEJIANG LINJIANG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] This route adopts high-pressure ammonification, the pressure is 3.0Mpa, the pressure is too large, the safety risk is great, and the ammonification and hydrolysis catalysts cannot be applied mechanically, and the yield of the product obtained is only 74% to 77%; at the same time, it uses sodium nitrite Participating in the diazotization reaction leads to the production of a large amount of dilute sulfuric acid containing salt, which has caused great troubles to the environmental protection, so its process needs to be improved

Method used

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  • Synthesis method of 3, 4, 5-trifluorophenol
  • Synthesis method of 3, 4, 5-trifluorophenol
  • Synthesis method of 3, 4, 5-trifluorophenol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] (1) Add 160g 3,4,5-trifluorobromobenzene and 6.4g Cu to a 1000mL autoclave 2 O-bipyridine catalyst, measure 480mL ammonia water (ammonia water concentration is 25%), add it to the autoclave, seal the autoclave, stir and heat up to 160℃, stirring speed 500r / min, reaction for 10h, the highest pressure during the reaction 1.5Mpa; Open the autoclave when it is lowered to room temperature, transfer the materials in the kettle for vapor distillation, the distilled materials are cooled to obtain a white solid, filtered and dried to obtain a white product of about 106.4g with a purity of 99.6% and a molar yield 95.1%;

[0040] (2) Add 300g of 98% concentrated sulfuric acid, 100g of water, and 147g of 3,4,5-trifluoroaniline to a 100mL three-necked flask, stir, heat up to 70℃ to dissolve, keep for 30min, cool to -5~0℃, drop Add 350 g of 40% nitrosyl sulfuric acid solution, drip and keep for 1 hour to obtain diazonium liquid for use;

[0041] (3) such as figure 1 As shown, add 450g o...

Embodiment 2

[0044] (1) Add 160g 3,4,5-trifluorobromobenzene and 6.4g Cu to a 1000mL autoclave 2 O-bipyridine catalyst, measure 480mL ammonia water (ammonia water concentration is 25%), add it to the autoclave, seal the autoclave, stir and heat up to 150℃, stirring speed 500r / min, reaction for 16h, the highest pressure during the reaction 1.3MPa; Open the autoclave when it drops to room temperature, transfer the materials in the kettle for vapor distillation, and obtain a white solid after cooling the distillate, which is filtered and dried to obtain a white product of about 103.2g with a purity of 99.6% and a molar yield 92.4%.

[0045] (2) 1000mL three-necked flask, add 300g concentrated sulfuric acid, 100g water, 147g 3,4,5-trifluoroaniline, stir, heat up to 70℃ to dissolve, keep for 30min, cool down to 0~5℃, add 40% nitrous acid dropwise 350g sulphuric acid, after dripping and holding for 1 hour, obtain diazonium liquid for use.

[0046] (3) such as figure 1 As shown, add 450g of sulfuric...

Embodiment 3

[0049] (1) Add 160g 3,4,5-trifluorobromobenzene and 6.4g Cu to a 1000mL autoclave 2 O-bipyridine catalyst, measure 400mL ammonia water (ammonia water concentration is 25%), add it to the autoclave, seal the autoclave, heat up to 160℃ with stirring, stir at 500r / min, react for 10h, the maximum pressure during the reaction 1.5MPa; Open the autoclave when it drops to room temperature, transfer the materials in the kettle for vapor distillation, and obtain a white solid after cooling the distillate, which is filtered and dried to obtain a white product of about 101.2g with a purity of 99.6% and a molar yield 90.6%.

[0050] (2) A 1000mL three-necked flask, add 300g of concentrated sulfuric acid, 100g of water, 147g of 3,4,5-trifluoroaniline, stir, heat to 70℃ to dissolve, keep for 30min, cool to -5~0℃, add 40% sub Nitrosulfuric acid 334g, after dripping and holding for 1h, the diazonium liquid is obtained for use.

[0051] (3) such as figure 1 As shown, add 450g of sulfuric acid solu...

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Abstract

The invention discloses a synthesis method of 3, 4, 5-trifluorophenol. The synthesis method includes following steps: taking 3, 4, 5-trifluorobromobenzene as a raw material, adding a certain volume ofammonia water and cuprous complexing catalyst, allowing heat-insulating reaction in a high-pressure kettle, and performing aftertreatment to obtain 3, 4, 5-trifluoroaniline; allowing 3, 4, 5-trifluoroaniline to be salified with sulfuric acid, being in diazotization reaction with nitroso-sulfuric acid, and hydrolyzing under copper salt catalysis to obtain 3, 4, 5-trifluorophenol. A hydrolysis device is introduced into a three-stage dichloromethane extraction device. Sulfuric acid concentration of a system is ensured to be constant, so that reaction yield is increased substantially. The synthesis method is easy-to-obtain in raw material and simple in process; the catalyst and the sulfuric acid are used for several times, so that raw material cost is low; the synthesis method is easy for industrialization and has good application prospect.

Description

Technical field [0001] The invention belongs to the field of preparation of pesticides, medicines, and liquid crystal material intermediates, and specifically relates to a synthesis method of 3,4,5-trifluorophenol. Background technique [0002] 3,4,5-Trifluorophenol is an important intermediate for the preparation of pesticides, medicines and fluorine-containing liquid crystal materials. In recent years, research on liquid crystal intermediates has found that fluorine-containing liquid crystal compounds can be used as fourth-generation TFT color liquid crystal materials. With better performance, it has broad development prospects. [0003] At present, the synthesis of 3,4,5-trifluorophenol mainly has the following routes: [0004] (1) Taking 3,4,5-trifluorobromobenzene as starting materials (JP10025261 and CN101445431), reacting with metallic magnesium to prepare Grignard reagent, and then reacting with boric acid ester to produce fluorobenzene borate, acidic conditions Under hydro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/27C07C37/045
CPCC07C37/045C07C209/10C07C245/20C07C211/45C07C39/27
Inventor 尹新吴文良杨江宇严泽华王启军
Owner ZHEJIANG LINJIANG CHEM
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